An amorphous alloy ribbon has excellent magnetic properties, and hence is utilized as a material for a magnetic core for power distribution or for a transformer, or a magnetic core for an electronic/electric circuit. When a magnetic core formed of a layered product of amorphous alloy ribbons is used, hysteresis loss and eddy current loss can be reduced, and hence no-load loss (core loss) can be reduced as compared to that of a transformer using silicon steel for its magnetic core.
An Fe-based amorphous alloy ribbon of an Fe—Si—B type or the like is used for the magnetic core for a transformer. In many cases, the amorphous Fe—Si—B-type alloy ribbon is produced by a liquid quenching method, in particular, a single-roll planer flow casting excellent in industrial producibility.
In the single-roll planer flow casting, an alloy material in a molten state (melt) is discharged onto a rotating chill roll, and the discharged melt is quenched and solidified on a surface of the chill roll. A production process of the amorphous alloy ribbon based on the single-roll planer flow casting is described in, for example, Patent Document No. 1.